1. Field of the Invention
This invention relates to a floor panel for use in making floor coverings, as well as a method for making the floor panel.
2. Related Art
More particularly, the invention relates to a floor panel which, at least at its edges, includes tongue-and-groove connection parts, which are made in one piece with the floor panel and shaped in such a manner that when coupled together along mutual edges by the tongue and groove coupling parts the floor panels are locked glue-free in a direction parallel to the plane of the panels and transverse to the edge connection, as well as in a direction perpendicular to this plane. Such floor covering panels are described in U.S. Pat. No. 6,006,486.
The floor panels can be joined together very fast by means of clicking and/or turning and are connected firmly without the necessity of using glue. It is also possible to disconnect these floor panels, after which they can be used again at another location.
When the floor covering is stepped on, it may occur that two adjacent panels undergo a minimal bending and, thus, carry out a movement in respect to each other. This movement is not unusual, as the floor panels are normally installed over an insulating and somewhat resilient underlay material.
This movement between the floor panels may result in a creaking noise, due to the friction which is created at the surfaces which are in contact with each other, because the coupling has locking surfaces associated with the tongue and groove parts between two panels which extend in a direction other than the horizontal direction (parallel to the principal plane of the panels).
It was noted that this phenomenon occurs with floor panels which are made of a material having a glued fibre-like wood based material, more particularly MDF or HDF.
In spite of the fact that by the use of tongue-and-groove connections made from MDF or HDF a rather smooth surface is obtained, as a result of which the aforementioned clicking and/or turning into each other takes place in a particularly easy manner, over the long term wear and tear may result from the mutual movement of the floor panels, as a result of which the trouble-free fitting of the floor panels can be influenced disadvantageously.
This invention in first instance has as an objective a floor covering panel in which the aforementioned and other disadvantages are avoided and, when being stepped upon, the creaking between the floor panels is avoided whereas over the long term the wear and tear of the tongue-and-groove connection also is limited.
According to the invention, this object is achieved in that a non-metallic sliding agent is applied on at least one of the panels at least at the location where the floor panels cooperate with each other, generally at the tongue-and-groove connection. The sliding agent is applied in the factory, for example, subsequent to the fabrication of the floor panels.
Due to the presence of this sliding agent, the floor panels, with the coupling parts of their tongue-and-groove connected, can slide over each other without thereby creating a perceptible sound. Due to the presence of the sliding agent, the friction, moreover, is reduced, as a result of which there is less wear and tear. If the sliding agent is provided at well-defined locations, this, as will be explained hereafter, also results in the floor panels being more easily joined, as the sliding agent reduces resistance during joining.
Preferably, a sliding agent is applied in the form of a layer which lies at least partially on top of the surface of one or both edges involved. By working with a layer on top of the surface, a good lubricating and sliding function is obtained.
According to a first possibility, the sliding agent is applied substantially over the entire surface of the edge of at least one of the floor panels.
According to a second embodiment, however, the sliding agent is applied in the form of one or more local strips extending in the longitudinal direction at the tongue-and-groove connection. Due to the provision of the sliding agent in the form of strips, it can easily be applied in a continuous process. Moreover, by applying such a strip locally, it is possible to avoid, due to the deformation of the sliding agent, that the latter is pushed beyond the tongue-and-groove connection, as a result of which a soiling at the upper side of the floor covering is avoided. Moreover, by local application in the form of a strip, the sliding agent can be applied efficiently at the location where it is desired, as a result of which the applied quantity can be kept limited.
The local application has also as an advantage that the strip may consist of a relatively thick layer of this sliding agent without creating any disadvantage.
More particularly, it is preferred that precisely one strip is applied.
Each respective strip in original, undeformed condition preferably has a maximum width of 4 mm.
The strip does not have to be continuous and may, for example, also consist of a succession of line portions, dots, and so on.
Preferably, the sliding agent is kept away from the upper edge of the floor panel, with the advantage that the sliding agent, when deformed, can not appear at the upper side of the floor covering. In first instance, this is of importance when a strip of some thickness is applied.
Specifically, it is preferred that between the upper edge and the strip of sliding agent that has been applied on a top area which is situated closest to the upper edge when seen along the contour of the surface, a receiving space is provided, as a result of which possible surplus sliding agent which is pressed aside can be taken up, so that the sliding agent cannot move up to the upper side. Such an intermediate receiving space may also be provided in the direction towards the lower edge.
As already becomes clear from the foregoing, preferably a deformable material is applied as a sliding agent.
More particularly, this sliding agent preferably is plastically deformable and, for example, meltable, but sets at room temperature, such that, during the manufacturing of the floor panels, it may be sprayed or be applied by means of a supply nozzle, in liquid form.
Suitable sliding agents are, amongst others, wax, in particular, paraffin.
It is noted that impregnating a tongue-and-groove of floor panels with paraffin is known but that this is performed to render the tongue-and-groove connection more resistive against the penetration of water. Hereby, the paraffin is applied over the entire surface of the tongue-and-groove and this in such a way that the paraffin completely penetrates into the surface. As a result thereof, this paraffin can not remedy the aforementioned problems arising with a tongue-and-groove connection engaged under a certain tension.
According to the invention, the sliding agent, more particularly, the paraffin, is applied in such a manner that a lubricating and/or sliding effect and, even better, a lubricating film is obtained. The necessary quantity of sliding agent depends on the material of the floor panels, the shape of the coupling and, eventually, when there is a tension between the floor parts, the value of this tension. This necessary quantity can be determined by tests.
In the case of a layer xe2x80x9clying on topxe2x80x9d, the thickness with which the sliding agent is provided, preferably is at least such that, at least with a glossy-looking sliding agent, a glossy surface remains visible after the application. More particularly, it is preferred that the layer of sliding agent in such case has an average thickness in the order of magnitude of 0.05 mm or more, although smaller thicknesses in principle are not excluded.
According to the invention, the tongue and/or groove can also be treated with a surface treatment product for sealing and/or hardening the surface, in which case the sliding agent is applied on top of this product, as a result of which the additional advantage is obtained that the sliding agent will not penetrate into the floor panels until after a certain period of time.
According to a particular embodiment of the invention, the surface of the edge of the floor panel is treated at least partially, but preferably entirely with a liquid mixture of at least one sealing agent and one sliding agent. By means of this treatment method which is performed in the factory, in one treatment a seal against humidity penetration, as well as a lubrication effect is obtained simultaneously. Such mixture has as a result that, after the application thereof on the milled tongue-and-groove profile, the sealing agent is absorbed in the material of the floor panel and fills the pores thereof, whereas the sliding agent remains at the surface. In this case, the sealing agent preferably is made of polyurethane, and the sliding agent of a wax, an oil or an oil-like substance.
The application of the mixture may take place in any manner, for example, by atomization, spraying, application by means of small rollers, etc.
More particularly the above-said sealing agent may be combined with the use of a strip of sliding agent applied on top, whereby then, at the location of this strip, a relatively thick layer of sliding agent is present, whereas a smaller quantity is present on the rest of the surface.
The tongue and the groove of the tongue-and-groove connection preferably have such a form that, in coupled position, they exert a certain tensioning force upon each other, in a preferred form of embodiment a tensioning force by means of which the mutually coupled floor panels are forced towards each other, in which case the strip of sliding agent is at least present on one or more portions of the contact surfaces of the tongue and/or the groove where this tensioning force is exerted or reacted. It is in fact at these portions where the largest friction occurs and the risk is greatest that an undesired noise will be created when the floor covering is stepped on.
According to a particular form of embodiment, the floor covering includes a tongue-and-groove connection comprising one or more portions which bend elastically when being joined together and taken apart, respectively, as certain portions of the coupling parts during joining and taking apart are forced over each other with a certain force. The aforementioned sliding agent at least is provided at the location of one or more of the portions which have to be forced over each other with a certain force. As a result thereof, the sliding agent also forms a lubricating agent, whereby fraying of the HDF or MDF is excluded, even if the floor panels are joined and taken apart repeatedly.
Moreover, in this case the sliding agent facilitates the mutual joining, by turning or clicking in, of the tongue and groove of a tongue-and-groove connection between two adjacent floor panels.
A portion of the floor panels defining the groove may be an elastically bendable lip, and the shape of the tongue and groove may be such that the tongue only fits into the groove by bending this lip and the sliding agent is applied on this lip or on the portion of the tongue opposite thereof.
The locking can be performed by a protrusion on the tongue and a recess in the wall of the groove. The sliding agent then preferably will be applied on this protrusion.
According to a particular embodiment, the risk for creating creaking sounds can also be avoided, or at least minimized, by using an elastic coating instead of a sliding agent. To this aim, an elastic coating is applied at least on one of the floor panels, at least at the location where the floor panels cooperate with each other, which coating, during a mutual shifting between the cooperating portions of the actual floor panels, enables local deformation in the material of the coating, as a result of which the risk of shifting at the contact surface between the coatings themselves, or between the coating and the surface of the other floor panel, is avoided or at least resisted and minimized.
This invention thus relates to a floor panel for a floor covering according to any of the preceding embodiments which is characterized in that it is provided by the factory on at least at one of its edges with a sliding agent or an elastic coating, as described above, as well as in the description below.